It is difficult to question evidence of this form, which bears the sign of hard physics as precise numbers produced by elaborate expensive instrumentation, because it requires knowledge of both instrument and processing of directly measured data, which both can be hidden in difficult technicalities.
Therefore the ditch in the spectrum, interpreted as a warming effect or "radiative forcing" from atmospheric CO2, has served CO2 alarmism as an "undeniable scientific fact" which cannot be questioned, with a warming effect of about 1 C upon doubling of atmospheric CO2. To refer to the spectrum has come to signify a deeper insight carried by both alarmists and skeptics, hidden to ordinary people not used to read spectra.
To question this "undeniable scientific fact" makes you into a "denier" destined to dwell on one of the lowest levels of Dante's Purgatorium.
In any case I have done so in a sequence of posts on OLR and I have come to the conclusion that the ditch in the spectrum attributed to CO2 is a misrepresentation of reality, or fabrication of fake evidence, similar to that of the "hockey stick", which started the fall of global warming alarmism.
I hope that skeptics are now read to question the OLR spectrum as the key evidence of CO2 warming with the same ardor as in the case of the hockey stick. Physicists have a special responsibility because the OLR spectrum is physics and not climate science.
But to be honest, very few seem to be interested in discussing the OLR spectrum, as if it is given once and for all by some superhuman intellect and thus beyond human understanding and scrutiny. But it is fabricated by people like you and me, and since it is the very basis of CO2 alarmism maybe some day someone will picks the thread. Since the first "hockey stick" attracted so much attention, may this new "hockey stick", if it is a "hockey stick", will deserve some as well.
Anyway, here are the key questions:
- How was the OLR spectrum produced?
- What was directly measured by the sensors, and what was computed in post processing?
- Does the spectrum describe reality with radiation "blocked" by CO2?
Maybe Fred Singer will then find reason to reconsider his message:
- I am opposed to those who criticize the global warming scare, basing it on what I consider to be incorrect physics. CO2 is certainly a greenhouse gas and should produce some increase in atmospheric temperatures but it is so small we cannot detect it.
If it is impossible to detect that "CO2 is a greenhouse gas", then it would be incorrect physics to declare that in any case "CO2 is a greenhouse gas". If ghosts cannot be detected, then it is not correct physics to nevertheless declare that "there certainly are ghosts" but they are "so small we cannot detect them". Right Fred?
PS1 WUWT reports:
- Following last night’s State of the Union Address in which the president pledged to implement a job-killing climate change agenda, U.S. Rep. Blaine Luetkemeyer (MO-3) today introduced legislation to prohibit the United States from contributing taxpayer dollars to the United Nations Intergovernmental Panel on Climate Change (IPCC) and the United Nations Framework Convention on Climate Change (UNFCCC).
- “The American people should not have to foot the bill for an international organization that is fraught with waste, engaged in dubious science, and is promoting an agenda that will destroy jobs and drive up the cost of energy in the United States,” Luetkemeyer said. “Unfortunately, the president appears to be ready to fund these groups, revive harmful policies like cap and trade, and further empower out of control federal regulators at a time when we should be doing everything possible to cut wasteful spending, reduce regulatory red tape, and promote economic growth.”
PS2 Fred does not seem to be willing to answer my question about the reality of the OLR spectrum, but I think the question asks for an answer.